U.S. patent application number 13/525857 was filed with the patent office on 2013-06-20 for pharmaceutical semi-solid composition of isotretinoin.
The applicant listed for this patent is Philippe Baudier, Cecile Servais, Francis Vanderbist. Invention is credited to Philippe Baudier, Cecile Servais, Francis Vanderbist.
Application Number | 20130158119 13/525857 |
Document ID | / |
Family ID | 3862550 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130158119 |
Kind Code |
A1 |
Vanderbist; Francis ; et
al. |
June 20, 2013 |
PHARMACEUTICAL SEMI-SOLID COMPOSITION OF ISOTRETINOIN
Abstract
Pharmaceutical semi-solid composition of Isotretinoin An oral
pharmaceutical composition of isotretinoin containing at least two
lipidic excipients, one of them being hydrophilic (i.e. having an
HLB value superior or equal to 10), the other being an oily
vehicle
Inventors: |
Vanderbist; Francis;
(Beersel, BE) ; Servais; Cecile; (Malonne, BE)
; Baudier; Philippe; (Uccle, BE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vanderbist; Francis
Servais; Cecile
Baudier; Philippe |
Beersel
Malonne
Uccle |
|
BE
BE
BE |
|
|
Family ID: |
3862550 |
Appl. No.: |
13/525857 |
Filed: |
June 18, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11892363 |
Aug 22, 2007 |
8367102 |
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13525857 |
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10380619 |
Jul 30, 2003 |
7435427 |
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PCT/BE01/00163 |
Sep 21, 2001 |
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11892363 |
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Current U.S.
Class: |
514/559 |
Current CPC
Class: |
A61P 17/00 20180101;
A61K 9/4866 20130101; A61K 47/44 20130101; A61P 17/10 20180101;
A61K 47/10 20130101; A61K 9/1075 20130101; A61K 9/0014 20130101;
A61K 31/202 20130101; A61K 9/4858 20130101; A61K 31/203
20130101 |
Class at
Publication: |
514/559 |
International
Class: |
A61K 31/202 20060101
A61K031/202 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2000 |
BE |
PCT/BE00/00111 |
Sep 21, 2001 |
IB |
PCT/IB00/00163 |
Claims
1-13. (canceled)
14. An oral pharmaceutical composition in the form of a capsule
comprising a semisolid suspension or a solution of isotretinoin and
at least a first and a second lipidic excipient, the composition
exhibiting a dissolution of at least 40% within 4 hours as measured
using USP paddle apparatus at 150 rpm in an aqueous dissolution
medium constituted by buffer of pH 7.5, sodium lauryl sulfate 2.5%
and pancreatin 1 g/L at 37.degree. C.
15. The oral pharmaceutical composition of claim 14, wherein the
composition exhibits an isotretinoin release rate of at least 60%
within 4 hours.
16. The oral pharmaceutical composition of claim 14, wherein
isotretinoin comprises between 1% to 25% w/w of the composition,
the first lipidic excipient comprises between 20% to 80% w/w of the
composition and the second lipidic excipient comprises between 5%
to 70% w/w of the composition.
17. The oral pharmaceutical composition of claim 14, wherein the
first lipidic excipient is selected from the group consisting of
glyceroyl macrogolglycerides, polyethylene glycol esters, and
mixtures thereof.
18. The oral pharmaceutical composition of claim 14, wherein the
second lipidic excipient is selected from the group consisting of
vegetable oils, medium chain triglycerides, fatty acid esters,
glycerol oleate and mixtures thereof.
19. The oral pharmaceutical composition of claim 14, wherein the
first lipidic excipient has a HLB value of at least 12.
20. The oral pharmaceutical composition of claim 14, wherein the
first lipidic excipient has a HLB value of at least 13.
21. The oral pharmaceutical composition of claim 14, wherein the
composition is a semi-solid suspension.
22. The oral pharmaceutical composition of claim 14, which further
comprises at least one surfactant.
23. The oral pharmaceutical composition of claim 22, wherein the
surfactant is selected from the group consisting of sorbitan fatty
acid esters, polysorbate compounds, polyoxyethylene sorbitan fatty
acids esters, sodium lauryl sulphate, compounds of lecithin,
propylene glycol esters, fatty acid esters of propylene glycol,
fatty acid esters of glycerol, mixtures thereof.
24. The oral pharmaceutical composition of claim 22, wherein the
surfactant comprises between 1% to 10% w/w of the composition.
25. The oral pharmaceutical composition of claim 14, which further
comprises at least one disintegrant.
26. The oral pharmaceutical composition of claim 25, wherein the
disintegrant is selected from the group consisting of crospovidone,
sodium croscarmellose, and mixtures thereof.
Description
ABSTRACT OF THE DISCLOSURE
[0001] The present invention relates to an oral pharmaceutical
composition of isotretinoin containing at least two excipients, one
of them being hydrophilic (i.e. having an HLB value superior or
equal to 10), the other being an oily vehicle.
THE PRIOR ART
[0002] Isotretinoin (13-cis retinoic acid or 13-cis vitamine A),
its isomers and some of its analogs are widely known to have a
therapeutical activity in the treatment of several severe skin
disorders like cystic acne, hypertrophic lupus erythematosus,
keratinization disorders. Some evidences have also been brought
about the activity of isotretinoin in basal cell carcinoma and
squamous cell carcinoma.
[0003] Unfortunately, isotretinoin is also a highly toxic drug.
Indeed, although isotretinoin, which is a cis derivative, is known
to be less toxic than all trans vitamine A derivatives, side
effects resulting from its use such as headache, vomiting,
irritation of mucosa and liver toxicity, occur frequently.
Furthermore, isotretinoin is known to be highly teratogenic in both
animals and humans.
[0004] In order to well understand the interest of this invention,
it is important to briefly summarize the physico-chemical
pharmacokinetic properties. Isotretinoin is a reddish-orange
powder. It is decomposed in presence of light and atmospheric
oxygen. Isotretinoin is very poorly soluble in water what mades its
bioavailability quite low after an oral intake (25% in fasted
conditions and 40% in fed conditions). The maximum concentration
(C.sub.max) is reached after 2-4 hours, while the (C.sub.max) of
the active metabolite, 4-oxo-isotretinoin is reached after 6 hours.
The elimination half-life of isotretinoin is of 7 to 37 hours while
the half life (t.sub.1/2) of the active metabolite is of 11 to 50
hours. The steady-state concentrations of isotretinoin are reached
after 1 week of treatment.
[0005] Very few publications and/or patents about the
pharmaceutical formulation of isotretinoin are available. The drug
is available on most markets under the form of a soft gelatine
capsule containing a fatty liquid formulation of isotretinoin.
[0006] The U.S. Pat. No. 4,464,394 describing for the first time
the therapeutical use of isotretinoin also describes briefly some
possibilities of compositions including it. It involves the use of
one antioxidant agent and of one carrier like lactose, starches or
polyethyleneglycols.
[0007] The EP patent 0184942 describes more specific compositions
of isotretinoin involving the use of one antioxidant, one chelating
agent, one pharmaceutical carrier and one suspending agent. The
composition obtained is stable during time.
[0008] The U.S. Pat. No. 4,545,977 relates to improved compositions
of isotretinoin wherein taurine is associated with isotretinoin to
reduce the side effects thereof.
[0009] The U.S. Pat. No. 5,716,928 describes a method for
increasing bioavailability and for reducing inter and intra
individual variability of an orally administered hydrophobic
pharmaceutical compound, which comprises orally administering the
pharmaceutical compound with an essential oil or essential oil
component in an amount sufficient to provide greater
bioavailability of the active ingredient.
[0010] The U.S. Pat. No. 6,028,054 relates to a method for
increasing bioavailability of an orally administered hydrophobic
pharmaceutical compound to human, which comprises orally
administering the pharmaceutical compound concurrently with a
bioenhancer comprising an inhibitor of e-cytochrome P450 3A enzyme
or an inhibitor of P-glycoprotein mediated membrane transport.
[0011] The U.S. Pat. No. 5,993,858 describes a self
microemulsifying excipient formulation for increasing the
bioavailability of a drug which includes an emulsion including an
oil or other lipid material, a surfactant and an hydrophilic
co-surfactant.
[0012] What is not described is a composition of isotretinoin
containing at least two lipid materials, one of them being
hydrophilic. The said composition may be a suspension, emulsion or
microemulsion.
BRIEF DESCRIPTION OF THE INVENTION
[0013] The advent of high throughput combinatorial chemistry and
efficient receptor based in vitro activity screen has resulted in
molecules with poor physicochemical (ex: dissolution) properties
for absorption across the gastro-intestinal tract, like
isotretinoin.
[0014] It is increasingly being recognized by the pharmaceutical
industry that for these molecules drug delivery systems play an
important role for improving oral bioavailability.
[0015] Although the process of passive diffusion is responsible for
absorption of non ionized lipophilic molecules via the
transcellular pathway, specialized absorption mechanisms,
first-pass metabolisms and efflux systems at the gastrointestinal
wall appear to play a major role for lack of absorption and poor
bioavailability for some molecules.
[0016] Isotretinoin is characterized by a low absolute
bioavailability and a high inter and intra individual variability.
Isotretinoin also presents a wide range of side effects among which
some are severe (ocular, skin anemia, hepatic, . . . ). It is
consequently of a particular interest to dispose of a reliable,
stable and highly bioavailable formulation of isotretinoin.
[0017] Several possibilities are available to the formulator to
increase the bioavailability of active ingredients (Table A).
TABLE-US-00001 TABLE A I. Use of salts, polymorphs. Precursors of
the active molecule (=prodrugs) II. Reduction of the particles'
size of the active principle and of the excipients used (by
trituration, grinding, micronization, precipitation controlled by
solvent, temperature or ultrasonics). III. Solid dispersions:
Eutectic mixes Solid solutions Vitreous solutions IV.
Recrystallization in an aqueous solution of a surfactant V.
Modification of the microenvironment: Hydrophilization pH
(acidification) VI. Incorporation of the active principle to
lipidic systems
It has been found that a semi-solid dosage form containing
isotretinoin was advantageous for obtaining a good bioavailability
of the isotretinoin. A semi-solid dosage form containing
isotretinoin is a form in which isotretoin is mixed with suitable
melted excipients. The molten mix is then filled for example into
hard gelatine capsules or other pharmaceutically acceptable
capsules. At ambient temperature (temperature for example of less
than 20.degree. C.), the content of the capsule is solid while at
temperature higher than 20.degree. C. (for example at temperature
greater or equal to 30.degree. C., advantageously greater or equal
to 35.degree. C., preferably substantially at body temperature
+/-37.degree. C.), it is liquid or semi-solid (paste). The
isotretinoin may be solubilized in the mix of excipients or
partially solubilized. The active ingredient may also be formulated
as a suspension, emulsion or microemulsion. Various lipidic
excipients are available to the formulator to obtain a semi-solid
formulation. Excipients compatible with hard gelatin capsule shells
are: lipophilic liquid vehicles (refined speciality oils,
medium-chain triglycerides and related esters), semi-solid
lipophilic vehicles, solubilizing agents, emulsifying agents and
absorption enhancers. The classification of fatty excipients is
based on the hydrophilicity or lipophilicity of the excipients,
characterized by the hydrophilic/lipophilic balance value (HLB).
Examples of lipophilic excipients are vegetable oils (peanut oil,
olive oil, soyabean oil, . . . ), fatty acids (stearic acid,
palmitic acid, . . . ), fatty alcohols, . . . Examples of
hydrophilic excipients are polyethyleneglycol (PEG) with a
molecular weight superior to 3,000. Examples of amphiphilic
(=presenting lipophilic and hydrophilic properties) excipients are
Poloxamers, Lecithin, PEG esters (Gelucire.RTM.), . . . .
[0018] The advantages of the semi-solid formulations of the
invention are multiple for isotretinoin: protection of the active
ingredient from air and humidity, possibility of increasing the
dissolution rate of the molecule and hence of the bioavailability,
diminution of the risk of contamination of the operator, diminution
of the risk of cross contamination, no possibility of demixing
under the effect of vibrational mixing during manufacturing
process, facility of the production process. The choice of the
nature of the formulation of course influenced the stability of the
pharmaceutical form and the bioavailability of the isotretoin
contained in it. Generally, a maximum bioavailability is achieved
by preparing and keeping the drug in the amorphous/solubilized
state in a solid dispersion or in a lipid-based formulation. For
these systems, the barrier we are avoiding is the compound
<<washing-out>> of solution to a large extent into a
insoluble crystalline form during the dissolution/release step in
vivo.
[0019] These systems may consist of suspension, emulsion,
microemulsion, self-emulsifying drug delivery systems (SEDDS.RTM.)
or self-emulsifying microemulsion drug delivery system
(SMEDDS.RTM.).
[0020] Microemulsions have the added advantage over suspensions
such as emulsions and dispersions since thermodynamically they are
more stable, that they can be manufactured with little energy input
and have generally a longer shelf-life. Nevertheless, a
microemulsion formulation is not a guarantee of higher
bioavailability in comparison to suspension a described
hereafter.
[0021] The formation of oil-in-water (O/W) and water-in-oil (W/O)
microemulsions usually involves a combination of 3-5 basic
compounds i.e. oil, surfactant, cosurfactant, water and
electrolytes. The challenge is to select for a particular
application oil(s) and surfactant(s) that are acceptable from a
toxicological perspective and that allow to obtain a high
bioavailability of the drug, i.e isotretoin.
[0022] The assessment of the quality of semi-solid lipid based
formulations is quite difficult since the in vitro dissolution test
is of little help. Indeed, the in vitro/in vivo correlation between
dissolution and bioavailability is very poor for this kind of
formulations. Other analytical tools are available to the
formulator to try to predict the in vivo bioavailability of
isotretinoin from various formulations like CACO-2 cells model, the
assessment of the percentage of drug dissolved in the formulation,
differential scanning calorimetry, microscopy, . . . .
[0023] Nevertheless, none of them present a guarantee of in
vitro/in vivo correlation and ultimately only pharmacokinetic
studies on human subjects are reliable to assess the
bioavailabiltiy of the drug.
DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
[0024] The pharmaceutical composition of the invention is an oral
semi-solid pharmaceutical composition of isotretinoin containing
two lipidic excipients, one of them being hydrophilic i.e. having a
HLB value of at least 10, for example equal to 10, but preferably
greater than 10, such as greater or equal to 12, for example
comprised between 12 and 14, and the other being an oily
vehicle.
[0025] The pharmaceutical composition of the invention contains
advantageously at least one hydrophilic excipient with a HLB value
of at least 10 selected from the group consisting of glyceroyl
macrogolglycerides, polyethyleneglycol derivatives, and mixtures
thereof. Preferably, the pharmaceutical composition contains from
20 to 80% by weight of hydrophilic excipient with a HLB value of at
least 10 selected from the group consisting of glyceroyl
macrogolglycerides, polyethyleneglycol derivatives, and mixtures
thereof.
[0026] The oily vehicle is selected from the group consisting of
vegetable oils, medium chain triglycerides, fatty acid esters,
amphiphilic oil, glycerol oleate derivative, and mixtures thereof.
For example, the composition contains from 5 to 70% by weight of an
oily vehicle selected from the group consisting of vegetable oils,
medium chain triglycerides, fatty acid esters, amphiphilic oil,
glycerol oleate derivative, and mixtures thereof.
[0027] According to another detail of preferred pharmaceutical
compositions of the invention, the composition further contains at
least one surfactant, preferably selected from the group consisting
of sorbitan fatty acid esters, polysorbate derivatives,
polyoxyethylene sorbitan fatty acid esters, sodium laurylsulphate,
derivatives of lecithine, propylene glycol esters, fatty acid
esters of propylene glycol, fatty acid esters of glycerol,
polyethylene glycol, and mixtures thereof. For example, the
composition contains from 1 to 10% by weight of at least one
surfactant.
[0028] Furthermore, the pharmaceutical formulation of the invention
contains advantageously at least one disintegrant, preferably
selected from the group consisting of povidone derivative, sodium
croscarmellose and mixtures thereof.
[0029] The pharmaceutical composition of the invention may contain
one or more surfactants and/or one or more disintegrants, but
contains preferably one or more compounds acting as surfactants and
one or more compounds acting as disintegrants.
[0030] The invention relates also to a pharmaceutical acceptable
capsule containing at least one semi-solid composition of the
invention, for example at least one composition of the invention as
disclosed hereabove. The capsule is for example selected from the
group consisting of hard gelatine capsules, soft gelatine capsules,
hypromellose capsules, starch capsules.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a ternary diagram of a formulation containing only
Gelucire.RTM. 50/13 and soyabean oil, the third component being
water;
[0032] FIG. 2 shows the dissolution rate of a reference product
(Roaccutane.RTM.--20mg active agent), of a suspension containing 20
mg Isotretoin and of an emulsion SEDDS.RTM. containing 10 mg
Isotretoin;
[0033] FIG. 3 shows an In vivo comparative pharmacokinetic profile
of isotretinoin;
[0034] FIG. 4 gives the comparative pharmacokinetic profile of
different formulations for isotretinoin,
[0035] FIG. 5 gives the comparative pharmacokinetic profile of
different formulations for 4-oxo-isotretinoin, the active
metabolite of isotretinoin and
[0036] FIGS. 6 and 7 describe the mean pharmacokinetic profile of
isotretinoin and 4-oxoisotretinoin for two formulations.
DESCRIPTION OF EXAMPLES
[0037] The present invention relates thus to a semi-solid
formulation of isotretinoin containing at least 2 lipidic
excipients, one of them being an hydrophilic excipient (having a
high HLB value namely>10) and the other an oily excipient. The
molten mix of these two excipients allows to totally or partially
(depending on the ratio between excipients) dissolve isotretinoin.
Different kinds of formulations (SEDDS.RTM. or suspensions) of
isotretinoin have been formulated. For suspensions, it was possible
to dissolve a high fraction of isotretinoin in the mix of
excipients and even the whole quantity of the active ingredient if
the manufacturing conditions (high temperature and long time of
mixing) and the formulations were optimized. Excipients
particluarly suitable for the dissolution of isotretinoin were
lauroyl Macrogol-32 glycerides (Gelucire.RTM. 44/14, Gattefosse)
and Stearoyl Macrogol-32 glycerides (Gelucire.RTM. 50/13,
Gattefosse). When those hydrophilic components are melted together
with an oily vehicle, it allows to obtain very stable suspensions
of isotretinoin in which an important part of the active ingredient
is dissolved. A surfactant may also be added to the formulation to
still improve the physical stability of the suspension.
[0038] SEDDS.RTM. formulations of isotretinoin are also stable and
may give an improved bioavailability of the drug.
[0039] Ternary diagrams allow to observe different areas
corresponding to different physical states namely coarse emulsion,
true emulsion, lamellar solution or micellar solution when the
ratio between excipients changes. The behaviour of the formulation
in presence of water changes when the ratio changes. One example of
this ternary diagram is given in FIG. 1 for a formulation of
isotretinoin containing Gelucire.RTM. 50/13 and soyabean oil.
EXAMPLES
Example 1
Effect of Different Lipophilic Compounds
[0040] The effect of different lipophilic excipients was evaluated
in the form of semi-solid capsules. The semi-solid capsules were
made by addition of the active substance at the pre-melted
lipophilic compounds followed by the filling of the liquid into
hard gelatin capsule.
[0041] The active substance was incorporated into formulations,
listed in table I, consisting of glyceroyl macrogolglyceride
associated with soyabean oil or derivative, medium chain
triglyceride.
TABLE-US-00002 TABLE I Formulations n.degree. 1 2 3 4 5 (mg)
Isotretinoin 20 20 20 20 20 Labrafil .RTM. M1944 CS 132 Gelucire
.RTM. 50/02 198 93 Gelucire .RTM. 44/14 217 Gelucire .RTM. 50/13 76
60 60 Soya bean oil 304 320 Mygliol .RTM. 320
The use of stearoyl macroglyceride (Gelucire.RTM. 50/13,
Gattefosse) and soyabean oil allows to obtain a formulation with a
dissolution profile similar to the reference (Roaccutane.RTM. 20
mg, Roche).
[0042] The formulation with labrafil or Gelucire.RTM. 50/02 are too
lipophilic to give a good dissolution in water.
[0043] In general, the use of an oily excipient can improve the
absorption of lipophilic drug by increasing the solubility of the
drug in the lipidic phase, but the release of the active ingredient
from the formulation can be slowed down due to the high affinity of
the drug for the oily phase.
[0044] The use of dispersed systems (emulsions or suspensions)
instead of only lipophilic or hydrophilic vehicles, improves the
absorption of the drug as well as increasing a larger contact
surface.
[0045] Concerning the Gelucire.RTM., the process of drug release
varies according to the HLB of the excipient. Gelucire.RTM. with
high HLB values were found to be the most favorable for a rapid
release of the drug (by diffusion and erosion).
[0046] The drug release profiles of the formulations 1 to 5 were
evaluated in phosphate buffer pH 7.5 with laurylsulfate and
pancreatin. The percent of isotretinoin released after 4 hours is
given in the following table II.
TABLE-US-00003 TABLE II percent of isotretinoin released after 4
hours Formulations n.degree. 1 2 3 4 5 % released 20.1 69.1 46.0
60.3 78.1
The percent of isotretinoin released from the reference
(Roaccutane.RTM. 20 mg) after 4 hours is 55.37%
Example 2
Influence of the Ratio Oily Vehicle/Surfactive Agent on the
Dissolution and Absorption of the Formulation
[0047] The study of the ratio oily vehicle/surfactive agent with
the construction of a ternary diagram gives information on the
dissolution profile of the formulation in water.
[0048] Stearoyl macrogolglyceride (Gelucire.RTM. 50/13) known as a
drug solubilizer and emulsifying agent of different drugs (in
SMEDDS.RTM. or SEDDS.RTM.) was tested in association with soyabean
oil.
[0049] This component has the ability to solubilize a great part of
isotretinoin in the formulation.
[0050] This is listed in table III
TABLE-US-00004 TABLE III Formulations n.degree. 1 2 3 4 5 6 (mg)
Isotretinoin 20 10 10 20 20 20 Soyabean oil 270 135 40 152 57 133
Gelucire .RTM. 50/13 84 42 200 228 323 247 Filling weight 374 187
260 400 400 400 Ratio oil/Gelucire .RTM. 3.2 3.2 0.2 0.67 0.17 0.54
50/13
[0051] In the presence of water, the behaviour of these
formulations are different [0052] formulations 1 and 2: formation
of coarse emulsion with large droplet sizes [0053] formulations 3
and 5: formation of micellar phase or microemulsion [0054]
formulations 4 and 6: formation of emulsion with homogeneous
droplet size
[0055] The percentage of isotretinoin released increases generally
with the percentage of Gelucire.RTM. in the formulation (increased
solubility of the active in this vehicle). For the formulation 1
(ratio oil/Gelucire.RTM. 50/13=3.2) 54.9% released after 4 hours
and for the formulation 3 (ratio oil/Gelucire.RTM. 50/13:0.2),
91.2% released after 4 hours.
Dissolution Test
[0056] For poorly soluble molecules, the prediction power of the in
vitro dissolution test is weak since the in vitro/in vivo
correlation is known to be poor. Nevertheless, an optimized
dissolution test (using enzymes and surfactant) is of some help to
assess the rate of release of the drug from the lipidic
composition. It must be noted that the conditions of the
dissolution (dissolution medium, speed of the paddles, temperature,
. . . ) test influence dramatically the results of the test and
should consequently be standardized to allow comparison between
various formulations.
[0057] The conditions of the solution test used for assessing the
dissolution of isotretinoin were the following: [0058] paddle
apparatus [0059] 150 rpm [0060] 37.degree. C. [0061] buffer pH 7.5
with laurylsulfate 2.5% and pancreatin 1 g/L
[0062] FIG. 2 shows the dissolution rate of a reference product
(Roaccutane.RTM. --20mg active agent), of a suspension containing
20 mg Isotretoin and of an emulsion SEDDS.RTM. containing 10 mg
Isotretoin (formulation given hereinbelow).
[0063] As the information brought by the dissolution test is poor
in term of correlation with in vivo bioavailability, it is of
interest to dispose of other means to predict the in vivo
bioavailability.
[0064] The caco-2 cell culture system can be used for determining
permeability of compounds (especially for poorly soluble
compounds). The caco-2 cell model allows to measure the transport
of drug from the apical to the serosal side as well as from the
serosal to the apical side. This allows to determine if an efflux
system is operational.
[0065] The caco-2 cells model is interesting because: [0066] The
cells used are from human origin (contrary to the models using
segments of animal's guts). They are coming from an adenocarcinoma
of the human colon but spontaneously differentiate into small
intestine's epithelail cells. When put in culture, they form a
monolayer of polarized cells expressing several enzymatic systems.
[0067] It offers a better prediction of the human intestine
absorption than the animals models [0068] The reproducibility of
the test is relatively high [0069] It allows to take samples from
both apical and basolateral sides
[0070] Caco-2 cells experiments have been performed with one
SEDDS.RTM. and one suspension isotretinoin formulations.
RESULTS
[0071] It was first proven that neither the active ingredient nor
the excipient used in the formulations were toxic for the cells. It
was also proven that the integrity of the membranes of the cells
was maintained during the whole experience.
Methodology:
[0072] The formulations tested are put in solution in 250 ml of
BME. Taurocholate (10 mM) was added to the solutions to better
mimate the in physiological conditions. The different solutions so
prepared are put in contact with Caco-2 cells at the apical or
basolateral side. The cells culture inserts) are incubated for 3
hours at 37.degree. C. and samples of 100 .mu.l are taken every
hours
[0073] The formulations tested were the following: [0074]
Formulation SEDDS.RTM. (batch number 26F97/1): [0075] Isotretinoin:
10 mg [0076] Gelucire.RTM. 50/13: 134 mg
[0077] Phospholipon 90.RTM.: 11 mg [0078] Tween 80.RTM.: 71 mg
[0079] IPP.RTM.: 24 mg [0080] Pro capsula una
[0081] Formulation suspension (batch number 25F97/1) [0082]
Isotretinoin: 20 mg [0083] Gelucire.RTM. 50/13: 83.7 mg [0084]
Soyabean oil: 270 mg [0085] Procapsula una
RESULTS
[0086] Passage of formulations from apical side.fwdarw.basolateral
side
TABLE-US-00005 Time SEDDS .RTM. Suspension SEDDS .RTM. + Suspension
+ minutes (26F97/1) (25F97/1) TC TC control 60 0.7721 0.6708 0.7019
0.6469 0.0718 120 2.4096 0.8749 1.4347 0.9513 0.1836 180 2.6226
1.1311 3.2419 1.5073 0.6156
Passage of formulations from basolateral side apical side
TABLE-US-00006 Time SEDDS .RTM. Suspension SEDDS .RTM. + Suspension
+ minute (26F97/1) (25F97/1) TC TC control 60 2.0496 0.3948 8.1291
0.8713 0.0650 120 3.0844 0.9068 8.3496 1.8460 0.1131 180 4.3653
1.0763 9.7110 2.0779 0.1481
The results demonstrate that the passage of isotretinoin is
superior for the SEDDS.RTM. formulation than for the suspension
formulation. In order to confirm these results, a comparative
pharmacokinetics study has been performed.
PK Studies
[0087] The bioavailability of SEDDS.RTM. (26F97/1) and suspension
(25F97/11) isotretinoin formulations has been assessed and compared
to the bioavailability of the reference (Roaccutane.RTM. 20 mg,
Hoffman LaRoche) on six healthy volunteers in a single dose, three
way, cross-over pharmacokinetic study). The drug was taken with
food (standardized breakfast). The plasma concentration of
isotretinoin and its active metabolite 4-oxo-isotretinoin were
quantified using a fully validated LC/MS/MS method.
[0088] The FIG. 3 described the mean pharmacokinetic profile
obtained for each formulation.
[0089] The following table gives the value of the main
pharmacokinetics parameters obtained for each formulation of
isotretinoin.
TABLE-US-00007 AUC.sub.72 h C.sub.max T.sub.max Formulations (ng
h/ml) (ng/ml) (h) Roaccutane .RTM. 20 mg 1747.89 116.63 1.83
(96C15315AA) Suspension 20 mg 4308.72 230.96 5.67 (25F97/1) SEDDS
.RTM. 10 mg 1494.64 98.36 3.00 (26F97/1)
It appears that both the SEDDS.RTM. and the suspension formulation
are able to significantly increase the bioavailability of
isotretinoin in comparison to the marketed reference. Indeed the
ratio between AUC.sub.72h of the supension 20 mg and
Roaccutane.RTM. 20 mg is of 2.47. The SEDDS.RTM. 10 mg present an
AUC.sub.72h similar to this of Roaccutane.RTM. 20 mg what means an
approximately 2-fold increase of bioavailability (ratio AUC.sub.72h
SEDDS.RTM. 10 mg/AUC.sub.72h Roaccutane.RTM. 20 mg=0.86).
Furthermore, the suspension and SEDDS.RTM. formulations both
presented a lower intraindividual variability of the
bioavailability as demonstrated by the values of relative standard
deviations (rsd) which are of 36.0%, 22.72% and 28.18% for
Roaccutane.RTM. 20 mg, suspension 20 mg and SEDDS.RTM. 10 mg
respectively.
[0090] Nevertheless, the results obtained in vivo are not
correlated with the results obtained on caco-2 cells since on this
model the permeability of the SEDDS.RTM. formulation was much
higher than the permeability of the suspension formulation while in
vivo the suspension formulation gives the best results.
[0091] A second pharmacokinetic study was performed on completely
different formulations (6 subjects, 2-way, fed, cross-over study).
Those were formulations of isotretinoin under the form of a
suspension in which the ratio between Gelucire.RTM. 50/13 and
soyabean oil was very different that the previous formulation of
suspension
[0092] The two formulations tested were the following: [0093] F1:
suspension without surfactant (batch number H23K99/1) [0094]
Isotretinoin: 20 mg [0095] Gelucire.RTM. 50/13: 247 mg [0096]
Soyabean oil: 133 mg [0097] F2: suspension with surfactant (batch
number H07L99/1) [0098] Isotretinoin: 20 mg [0099] Gelucire.RTM.
50/13: 240 mg [0100] Soyabean oil: 130 mg [0101] Span 80.RTM.: 20
mg
[0102] The FIG. 4 gives the comparative pharmacokinetic profile of
each formulation for isotretinoin
[0103] The FIG. 5 gives the comparative pharmacokinetic profile of
each formulation for 4-oxo-isotretinoin, the active metabolite of
isotretinoin.
[0104] In order to confirm the first bioavailability data obtained
with the present invention, a larger pharmacokinetic study has been
performed.
[0105] The bioavailability of a capsule of isotretinoin 16 mg (see
the formulation herebelow) from the present invention has been
assessed and compared to the bioavailability of the reference
(ROACCUTANE.RTM. 20 mg capsule, Roche) on 24 healthy subjects.
[0106] This study (SMB-ISO-SD011) was a single dose, two treatment,
two period, two sequence, randomised, crossover and with at least
18 days wash-out between the two periods.
[0107] The subjects were healthy caucasian volunteers of both sexes
(non-pregnant, non-breast-feeding), aged 18 to 50 years, non
smokers or smoking less than 10 cigarettes per day.
[0108] The drugs was taken with food (a standardized
breakfast).
[0109] Blood samples were collected according to the following
sampling schedule: pre-dose and 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h,
8 h, 10 h, 12 h, 14 h, 24 h, 36 h, 48 h, 72 h, 96 h, 120 h, 168 h
and 216 hours post-dose.
[0110] The plasma concentration of isotretinoin and its active
metabolite 4-oxo-isotretinoin were quantified using a fully
validated LC/MS/MS method. The continuous variables were evaluated
according to an univariate ANOVA, based on log-transformed data.
The Wilcoxon non-parametric ANOVA were used where appropriate.
Bioequivalence was evaluated using the Shuirman two one-sided
t-test (90% Cl) and the westlake single sided confidence interval
(95% CL)
[0111] The FIGS. 6 and 7 describe the mean pharmacokinetic profile
of isotretinoin and 4-oxoisotretinoin for the two formulations
(n=24 subjects) while the tables herebelow give the comparative
main pharmacokinetic parameters.
[0112] Formulation of isotretinoin 16 mg (mg/capsule)
TABLE-US-00008 isotretinoin 16 stearoyl macrogol glycerides
(Gelurire 50/13 .RTM.) 192 soya bean oil refined 104 sorbitane
oleate (Span 80 .RTM.) 16
As seen, the dose of 16 mg of the formulation corresponding to the
present invention gives a bioavailability similar to 20 mg of the
marketed formulation, what is the evidence of the
supra-bioavailability of the formulation corresponding to the
present invention.
[0113] The tables hereinbelow gives the value of the main
pharmacokinetics results and statistical analysis obtained for each
formulation of isotretinoin and 4-oxoisotretinoin.
[0114] This study demonstrated that ROACCUTANE.RTM. 20 mg and
isotretinoin 16 mg x are bioequivalent after a single oral dose
administration of each product in fed conditions. Indeed, the
primary parameters AUC (AUC.sub..infin. and AUC.sub.216 h) were
within the predetermined confidence interval.
[0115] This study demonstrated also that Isotretinoin 16 mg has a
safety profile comparable with that described in the literature for
other isotretinoin preparations and similar to this of
ROACCUTANE.RTM. 20 mg.
[0116] Pharmacokinetic results and statistical analysis of
comparative study in 24 volunteers for isotretinoin
(log-transformed data)
TABLE-US-00009 Bioequivalence tests Results Shuirman Westlake
Parameter ROACCUTANE .RTM. 20 mg Isotretinoin 16 mg 90% CI Range
95% CL AUC.sub..infin. 5657.09 (ng h/ml) 5696.92 (ng h/ml) 92-123
19.07 .+-. SD .+-. 2682.98 .+-. 1938.89 .+-. RSD .+-. 47.42 .+-.
34.03 AUC.sub.216 h 5601.36 (ng h/ml) 5664.39 (ng h/ml) 92-124
19.51 .+-. SD .+-. 2670.85 .+-. 1953.52 .+-. RSD .+-. 47.68 .+-.
34.48 C.sub.max 386.68 (ng/ml) 441.79 (ng/ml) 103-140 28.81 .+-. SD
.+-. 218.21 .+-. 197.43 .+-. RSD .+-. 56.43 .+-. 44.68 T.sub.max
4.92 (h) 4.50 (h) / / .+-. SD .+-. 2.22 .+-. 0.66 .+-. RSD .+-.
45.24 .+-. 14.65
[0117] Pharmacokinetic results and statistical analysis of
comparative study in 24 volunteers for 4-oxoisotretinoin
(log-transformed data)
TABLE-US-00010 Bioequivalence tests Results Shuirman Westlake
Parameter ROACCUTANE .RTM. 20 mg Isotretinoin 16 mg 90% CI Range
95% CL AUC.sub..infin. 5750.36 (ng h/ml) 5769.04 (ng h/ml) 92-124
19.65 .+-. SD .+-. 2717.38 .+-. 2161.97 .+-. RSD .+-. 47.26 .+-.
37.48 AUC.sub.216 h 5638.32 (ng h/ml) 5712.21 (ng h/ml) 92-125
20.46 .+-. SD .+-. 2704.73 .+-. 2126.61 .+-. RSD .+-. 47.80 .+-.
37.23 C.sub.max 111.52 (ng/ml) 115.15 (ng/ml) 94-125 20.18 .+-. SD
.+-. 69.62 .+-. 66.25 .+-. RSD .+-. 62.43 .+-. 57.53 T.sub.max
17.83 (h) 16.33 (h) / / .+-. SD .+-. 10.60 .+-. 10.11 .+-. RSD .+-.
59.43 .+-. 61.88
* * * * *